layoutitem.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2015 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "layoutitem.h"

 LayoutItem::LayoutItem(QGraphicsItem *parent/* = 0*/)
     : QGraphicsLayoutItem(), QGraphicsItem(parent)
 {
     m_pix = new QPixmap(QLatin1String(":/images/block.png"));
     setGraphicsItem(this);
 }

 LayoutItem::~LayoutItem()
 {
     delete m_pix;
 }

 void LayoutItem::paint(QPainter *painter,
     const QStyleOptionGraphicsItem *option, QWidget *widget /*= 0*/)
 {
     Q_UNUSED(widget);
     Q_UNUSED(option);

     QRectF frame(QPointF(0,0), geometry().size());
     qreal w = m_pix->width();
     qreal h = m_pix->height();
     QGradientStops stops;

     // paint a background rect (with gradient)
     QLinearGradient gradient(frame.topLeft(), frame.topLeft() + QPointF(200,200));
     stops << QGradientStop(0.0, QColor(60, 60,  60));
     stops << QGradientStop(frame.height()/2/frame.height(), QColor(102, 176, 54));

     //stops << QGradientStop(((frame.height() + h)/2 )/frame.height(), QColor(157, 195,  55));
     stops << QGradientStop(1.0, QColor(215, 215, 215));
     gradient.setStops(stops);
     painter->setBrush(QBrush(gradient));
     painter->drawRoundedRect(frame, 10.0, 10.0);

     // paint a rect around the pixmap (with gradient)
     QPointF pixpos = frame.center() - (QPointF(w, h)/2);
     QRectF innerFrame(pixpos, QSizeF(w, h));
     innerFrame.adjust(-4, -4, +4, +4);
     gradient.setStart(innerFrame.topLeft());
     gradient.setFinalStop(innerFrame.bottomRight());
     stops.clear();
     stops << QGradientStop(0.0, QColor(215, 255, 200));
     stops << QGradientStop(0.5, QColor(102, 176, 54));
     stops << QGradientStop(1.0, QColor(0, 0,  0));
     gradient.setStops(stops);
     painter->setBrush(QBrush(gradient));
     painter->drawRoundedRect(innerFrame, 10.0, 10.0);
     painter->drawPixmap(pixpos, *m_pix);
 }

 QRectF LayoutItem::boundingRect() const
 {
     return QRectF(QPointF(0,0), geometry().size());
 }

 void LayoutItem::setGeometry(const QRectF &geom)
 {
     prepareGeometryChange();
     QGraphicsLayoutItem::setGeometry(geom);
     setPos(geom.topLeft());
 }

 QSizeF LayoutItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
 {
     switch (which) {
     case Qt::MinimumSize:
     case Qt::PreferredSize:
         // Do not allow a size smaller than the pixmap with two frames around it.
         return m_pix->size() + QSize(12, 12);
     case Qt::MaximumSize:
         return QSizeF(1000,1000);
     default:
         break;
     }
     return constraint;
 }